Project Structure

The project is structured with several servlets, each handling different parts of the application:

1. handleLogin Servlet: Manages user authentication.
2. HandlePlayer Servlet: Handles player actions such as play, pause, stop, and broadcast.
3. Host Servlet: Handles file uploads and sets up the server socket for streaming.
4. Join Servlet: Provides a web interface for users to join the music stream.
5. Stream Servlet: Streams audio data from the host to clients.

1. Handle Login Servlet

The handleLogin servlet is responsible for authenticating users. Here’s a step-by-step breakdown of its functionality:

• Receiving Credentials: When a user submits their username and password through a login form, the servlet receives these credentials via a POST request.
• Validation: The servlet checks if the provided username and password match the expected values (in this case, both are “admin”).
• Session Management: If the credentials are correct, a new session is created for the user, and their username and password are stored as session attributes. This helps in maintaining the user’s authenticated state across multiple requests.
• Redirection: Authenticated users are redirected to the hostServer.jsp page, while unauthenticated users are redirected to a join page (Join).

This servlet ensures that only authorized users can host a music stream, adding a layer of security to the application.

2. Handle Player Servlet

The HandlePlayer servlet handles various playback actions sent by the client. Here’s how it works:

• Action Handling: The servlet receives an action parameter (e.g., play, pause, stop, broadcast, back) from the client.
• Logging Actions: Based on the action parameter, the servlet logs a message to the server console.
• Navigation: If the action is “back,” the servlet redirects the user to the hostServer.jsp page. For other actions, it redirects the user to the player.jsp page.

This servlet provides a basic framework for controlling music playback and navigation within the application.

3. Host Servlet

The HostServlet servlet is central to the application’s functionality. It handles file uploads and sets up a server socket for streaming audio. Here’s a detailed breakdown:

• Initialization: During servlet initialization, a server socket is created on port 6000, and a separate thread is started to accept client connections.
• File Upload Handling: When a user uploads an audio file via a POST request, the servlet:
  • Saves the uploaded file to the server.
  • Extracts the file name and stores it in the session.
  • Redirects the user to the player.jsp page, where the audio can be played.
• Client Handling: The servlet continuously listens for client connections. When a client connects, a new thread is spawned to handle streaming the audio file to the client.

This servlet demonstrates how to handle file uploads and implement real-time streaming using sockets.

4. Join Servlet

The JoinServlet servlet provides an interface for users to join the music stream. Here’s how it works:

• Generating HTML: The servlet generates an HTML page with an embedded audio player that automatically plays the streamed audio.
• Displaying Information: The page includes details about the currently playing song, retrieved from the session.

This servlet ensures that users have a user-friendly interface to join and listen to the music stream.

5. Stream Servlet

The StreamServlet servlet streams audio data to connected clients. Here’s a step-by-step explanation:

• Client Connection: When a client requests the stream, the servlet connects to the host server socket.
• Data Streaming: The servlet reads audio data from the host and writes it to the client’s output stream, ensuring real-time audio playback.

This servlet is crucial for delivering the audio content from the server to the client.

Benefits

The music streaming server has several benefits, including:

• Real-time Audio Streaming: The server allows for real-time audio streaming, which means that clients can listen to the audio file as it is being played by the host.
• Multi-client Support: The server supports multiple clients, which means that multiple users can join the music stream and listen to the audio file simultaneously.
• User Control: The host has control over the playback of the audio file, which means they can pause, stop, or broadcast the audio file as needed.

Key Concepts and Features

User Authentication

The handleLogin servlet manages user authentication. It checks the provided username and password and creates a session for authenticated users. This is crucial for ensuring that only authorized users can access certain parts of the application.

File Upload

The Host Servlet servlet handles file uploads using the @MultipartConfig annotation. This allows users to upload audio files, which are then saved on the server and streamed to clients.

Socket Programming

The HostServlet sets up a server socket to accept client connections. The StreamServlet connects to this socket to receive the audio data. This demonstrates basic socket programming in Java, which is essential for real-time data streaming.

Client-Server Communication

The application demonstrates how to handle client-server communication using servlets. The JoinServlet and StreamServlet work together to stream audio data from the server to the client, providing a seamless music streaming experience.

Conclusion

Building a music streaming web application with Java Servlets involves various components, including user authentication, file uploads, and socket programming. By understanding and implementing these components, you can create a functional and interactive web application. This example serves as a foundation for more advanced features and functionalities that you can add to enhance the user experience.